One of the enduring images from this T20 World Cup, especially for a South African fan, will be yet another batter done in by a Lungi Ngidi slower ball.
Fittingly, Ngidi trapped Ryan Burl lbw on Sunday with his off-cutter to take his 90th T20I wicket, the most by a South African man, and third-most overall behind Shabnim Ismail and Marizanne Kapp.
The broadcast showed that at 114.3 kmph, the wicket ball was 23.5 kmph slower than the previous delivery. “Dips on you, it comes out of the top of the hand, almost like Dwayne Bravo,” remarked Proteas great Shaun Pollock on commentary.
Last week, even as he went wicketless against India, Ngidi was the talk of the town for a restrictive spell of 0-15 in four overs. After that match, he told the media how he had used his time on the Chennai Super Kings bench during the 2018 IPL to pick up the art of the slower ball, from none other than Bravo.
But what exactly did he pick up? And what makes the slower balls of these two players in particular so hard to play?
In cricketing terms, Ngidi’s primary slower ball is the off-cutter. It is one of the most common variations for a seam bowler to have; right-armers roll the fingers down the right side of the ball to add spin to the ball, bringing down its speed as well as giving it the chance to bounce, grip in the surface and deviate from left to right.
Bowlers are generally taught to bowl the off-cutter with a key/doorknob analogy: “You put your key in the door, and you turn it” (Brett Lee) or “like you’re just opening a door” (Simon Doull).
What Bravo did, and seemingly Ngidi does, is slightly different, and perhaps needs a change in the way we classify variations in cricket.
What can baseball tell us about cricket's slower balls?
To explore this further, we can look to the sport’s closest cousin, baseball.
The role of the pitcher in baseball is analogous to cricket’s bowler – the key differences being that the pitcher is allowed to bend and extend their elbow, and they do not bounce the ball before it reaches the batter. Adding spin to a ball being thrown or bowled can happen in three dimensions, as illustrated below by Rockland Peak Performance.
Spin bowlers often bring types (A) and (B) into play, but these are rarely talked about when it comes to quicker bowlers. The off-cutter taught to pace bowlers is almost exclusively type (C). Here, the imaginary line about which the ball rotates (axis of rotation), shown in red above, is along the same direction it travels in.
In baseball, each of these types of spin added to a pitch is considered a different variation. (A) is known as a ‘sweeping slider’ or ‘sweeper’, (B) is a ‘sinker’ and (C) is a ‘slider’, or sometimes more specifically a ‘gyro slider’.
The aim of the gyro slider is to stabilise the flight path of the ball – ensuring there is no extra horizontal or vertical movement in the air. The idea is to make the ball travel as straight as possible until gravity ‘tips’ it to dip sharply. The reason this happens is that when a ball is spun about an axis along its direction of travel, Magnus force, which causes movement in the air, does not take effect.
When throwing the sweeper, pitchers must angle their wrist to move their fingers “around” the ball, i.e. from back to front, to spin it around the axis shown in (A).
Spinning it in this way allows the Magnus force to come into play, and the ball will now dip slightly less, but has the added component of moving horizontally in the air – what we would term ‘drift’ or ‘swing’ in cricket parlance. Yu Darvish and Shohei Ohtani are two of the most prominent pitchers who throw the sweeper.
As far as type (B) is concerned, throwing a ball with overspin will cause it to dip faster and land shorter than expected, while one with extra backspin may ‘lift’ and land fuller than expected.
Now, there are always components of spin in all three dimensions, i.e. it is extremely rare that one might spin a ball purely along exactly one of these directions. But by and large, the direction in which a pitcher applies the spin will be dominant.
So, what does all this have to do with off-cutters?
The following clip of Super Kings bowling coach Eric Simons illustrates the difference between a ‘normal’ off-cutter and the Bravo off-cutter.
The ‘normal’ one is analogous to the gyro slider. While going through the air, its flight is relatively stable. But baseball pitchers can rely on late ‘drop’ since they propel it in a straight line, and gravity will act later in the flight to drag it down. Cricket’s bowlers do not have this luxury. Since they need to bounce the ball, it is already heading downwards and there is no surprise element for the batter on that front.
In essence, the most advantageous component of the gyro slider is far less of a factor in cricket. What the ‘normal’ off-cutter does retain is the drop in pace from a stock ball, and the potential to grip in the surface. The off-cutter that Bravo and Ngidi bowl retains those two aspects. But the release is far closer to baseball’s sweeper, as Simons shows.
Therefore, instead of trying to stabilise the ball path with the ‘gyro spin’, the side spin (A) and over spin (B) both become more dominant. The former can induce horizontal movement, challenging the batter on line. The latter can induce ‘dip’, challenging the batter on length.
The following clip should illustrate the difference between the two types slightly more clearly.
Dale Steyn had a similar ‘sweeping’ release for this incredible slower ball to Jonny Bairstow. Here is an excellent example of Ngidi troubling the batter on both line and length in the air; notice how the ball curves a touch to the left and drops sharply at the end of its flight.
Now retired, towards the end of his T20 career, it was largely noted that Bravo’s slower balls had begun to lose their effectiveness. Indeed, from ball-tracking data available in the IPL between 2022 and the first half of 2025, he ranked 57th out of 83 pacers for the amount of sideways movement on their fuller slower balls (minimum 5 balls bowled, below 125 kmph and fuller than 7 metres).
At present, Ngidi is one of the few pacers that primarily bowls the ‘sweeping’ off-cutter. Jasprit Bumrah is the other prominent example – remember his incredible deliveries to Shaun Marsh and Ollie Robinson in Test cricket – but he tends to go between this and the conventional off-cutter, suggesting it may be natural variation in the way he flicks his wrist to impart the spin. At his best, Harshal Patel also wreaked havoc in the IPL with a similar release.
The types of deliveries discussed here deal with spin along two of the axes mentioned before. The third is largely treated as a separate variation; the back-of-the hand slower ball, where bowlers will twist their wrist around and pull down the front of the ball.
But there is a version of applying overspin on the ball that remains under the classification of an off-cutter; Mustafizur Rahman’s, which sees him manipulate his wrists in almost mind-bending fashion.
It’s clear that he doesn’t just roll down the side of the ball. But he doesn’t apply spin the way Ngidi and Bravo do, either. Mustafizur comes up and over the ball, pulling down on the front to induce ‘drop’, more than anything else. This is roughly analogous to the ‘sinker’ in baseball. A crucial difference between the sports is that the bowler can benefit from extra bounce after the ball lands, while the pitcher cannot.
In the IPL set mentioned earlier, Mustafizur ranked third for how much his slower ball accelerated downwards after release (i.e., dropped). Nathan Ellis, Yash Dayal, Rasikh Salam, Chetan Sakariya and Mohit Sharma, the others in the top seven, all bowl a significant proportion of back-of-the-hand slower balls.
Our sport currently does not differentiate between these three types of deliveries; they all fall under the umbrella of off-cutters. But the three require different actions to release, and behave differently as they head towards the batter. Baseball recognises this, and since 2023 the sweeper has been classified separately from the slider.
Perhaps cricket should follow suit; after all, it is little more than recognising the beautiful variety of skills players bring to their craft.
Footage credit: JioHotstar
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